Vessel for quenching cast sheeting

ABSTRACT

The surface of water used to quench cast polyethylene terephthalate sheeting is kept smooth by use of a weir tray which isolates all but a &#39;&#39;&#39;&#39;slot of water&#39;&#39;&#39;&#39; from the cast sheeting.

United States Patent 191 Schindler VESSEL FOR QUENCHING CAST SHEETING [75] Inventor: Roger N. Schindler, Fairport, NY.

[73] Assignee: Eastman Kodak Company,

Rochester, NY.

22 Filed: Mar. 13,1970 21 Appl.No,:19,334

[52] US. Cl 425/71, 264/216, 134/122, 134/155, 425/224 [51] Int. Cl B29d 7/00 [58] Field of Search 18/10,15 R, 15S, 15 F, 18/26 R, 14 R, 14 (1,14 S; 264/212, 216,

[56] 1 References Cited UNlTED STATES PATENTS Edwards 18/15 S [451 July 16, 1974 3,337,663 8/1967 Taga 18/14 S 3,358,980 12/1967 Taylor 266/3 3,377,413 4/1968 Jansson et a1. 264/95 7 Merten 18/15 F X Primary ExaminerJ. Spencer Overholser Assistant ExaminerDavid. S. Safran Attorney, Agent, or Firm-K; Donald Fosnaught 57 ABSTRACT The surface of water used to quench cast polyethylene terephthalate sheeting is kept smooth by use of a weir tray which isolates all but a slot of water from the cast sheeting.

4 Claims, 3 Drawing Figures 1 VESSEL FOR QUENCHING CAST SHEETING BACKGROUND OF THE INVENTION water. As particularly pointed out in such patent appli-' cation, in order to cast essentially optically perfect (mark-free) polyethylene terephthalate sheeting, it is necessary to keep the surface of the water in question extremely smooth, though nonstagnant, and it is to this requirement that the present invention is directed.

SUMMARY OF THE INVENTION The invention provides a vessel having a specially disposed weir tray which effectively assures that, at the sheet submersion point, the surface of the water is extremely smooth. The weir tray is so designed that the submerging sheet plunges through a water slot. Water is circulated through the vessel; and such circulating water is prevented from entering the tray, except through the water slot, by means of flanges which ride against the casting wheel. A weir, disposed at one side of the tray, causes water within the weir tray to flow out of the tray in the form of a spread; and similarly, a weir disposed at the inlet to the vessel assures the evenentry of water into the vessel compartment which actually contains the partially submerged casting wheel. The sides and bottom of the weir tray prevent turbulence and the like at the surface of the water in the vessel from adversely affecting the optical quality of they cast polyethylene terephthalate sheeting by effectively isolating the water in the tray from the water in the vessel,

' i.e., water can enter the tray only via the water slot.

Thus, the cast sheeting sees only the water in the tray; and that wateris effectively smooth.

The invention will be described with reference to the figures, wherein FIG. 1 is a side elevational view depicting apparatus according to the invention,

FIG. 2 is a plan view of the apparatus of FIG. 1, taken generally along lines 22 thereof, and

FIG. 3 is a perspective view illustrating the cooperation between a weir tray, according to the invention, and a casting wheel.

With reference to the figures, a casting wheel is shown in cooperation with an extrusion die 12 which lays a coating of molten polyethylene terephthalate 14 on the wheel. The casting wheel 10 is supported for partial submersion in water contained within a vessel 16 designed according to the invention.

2 permitted to enter the inlet compartment 18 via a valve 24. A wall 26 between the inlet and main compartments 18, 20 constitutes a weir which serves to distribute the water within the inlet compartment 18 so that if flows evenly, i.e., does not gush, into the main compartment 20.

The level of the water in the main compartment 20 is essentially controlled by overflow of water fromthe weir tray 22:

The bottom 28 of the weir tray 22 is disposed parallel to and near the water surface which is to be maintained smooth. A pair of sides 30, upstanding from the bottom of the tray 28, cooperate to confine water, which is within the tray 22, to flow over a weir 32 into a drain basin 34. The height of the weir 32 is less than .the height of the tray sides 30, so that water flow, necessarily, is from tray-to-drain basin. Brackets 33 are provided to facilitate the substitution of various size tray weirs as may be required.

Supported by the tray sides 30, and extending respectively therefrom to contact with the casting wheel 10, are a pair of flanges 36. As indicated, the bottommost part 38 of the flanges 36 extend beyond the bottom 28 of the tray; and the flanges 36 are disposed so as to define a water slot 40, between the tray 22 and the wheel 10 sheeting 14, and through which slot water may flow to enter the tray 22. The flanges 38 are preferably of a nylon-like material, thereby to prevent their scratching the surface of the casting wheel 20.

The action of a partially submerged, rotating, casting wheel is'to draw water downwardly on one side of the wheel, and upwardly on the other. Needless to say, such seesawing at the water surface creates standing waves, splashing, and the like, which attendantly cause corruption of the optical quality of sheeting cast on the wheel. By means of the invention, vertical movement of the water surface at the immersion side of the wheel is effectively damped since waves and the like within the water are prevented from reaching the water within the tray except via the water slot 40; and since such slot is comparatively narrow, water sloshing,.etc, within the I tions can be effected within the spirit and scope of the The vessel 16 has essentially three discrete compart- 6 ments, viz. an inlet compartment 18, a main compartment 20, and a weir tray (compartment) 22. Water is invention. For example, it would be within the purview of the invention to make the weir tray in the form of a shelf that is within and forms part of the main compartment 20. Other modifications are possible also.

What is claimed is:

1. In combination,

a. a casting wheel,

b. a vessel cooperative with said casting wheel for liquid may flow from the vessel into the said tray,

d. means for causing a flow of liquid from said vessel into said tray and thence over said weir,

e. and in addition, including means, extending from the sided part of said tray, adapted to bear against the said casting wheel to prevent liquid from entering the said tray except through the said passageway.

2. The combination of claim 1 wherein said means adapted to bear against the said casting wheel is comprised of a nylon-like material.

3. The combination of claim 1 including 

2. The combination of claim 1 wherein said means adapted to bear against the said casting wheel is comprised of a nylon-like material.
 3. The combination of claim 1 including a. a valve for discharging liquid into said vessel, b. an inlet weir disposed within said vessel beTween said valve and said casting wheel, thereby to define inlet and main compartments of the said vessel, said inlet weir being sufficiently high so that liquid flows thereover from said inlet compartment into said main compartment.
 4. The combination of claim 3 including bypass valve means in said main compartment for regulating the flow of liquid which may pass into said tray via said passageway. 